One of the main advantages of MPLS is the prioritization. The administrator gives priority based on type of traffic, source port number etc. If bandwidth is not enough for all traffic, then only traffic with higher priority travels. When we use cable, we know exactly maximum bandwidth, but when we use WiFi we know "up to this" bandwidth. How does the administrator divide traffic with priority if s/he does not know exactly bandwidth of links?
Wimax standard already supports Qos and has a predefined set of 5 classes for supporting different QoS. In Wimax the CAC( Call Admission Control) would check first if the requested flow can be admitted with requested QoS hence there is no " Up to this Bandwith) concept, Based on the channel condition of users ( CQI ) scheduler mechanism will decide which traffic will be travels or will be delayed. have in mind MAC layer of WiMaX is connection oriented .
Yes, but I ask about backbone, where one part consist from SDH/MPLS/IP and new is with WiMax/IP. How I will use priority of traffic from the first part to the second?It must redefine priority to the classes and I lose one/two level of granularity of traffic. In which RFC it is explained? Thank you once again in advance.
Dear Veneta , i am not much qualify to talk about backbone as it is not my field of study, but generally in case of wireless systems the assumption is that the backbone is " overprivisoned" and the bottleneck is the wireless air interface, I guess Wimax system methodology V2.1 can give you some idea about implementation of backbone network for base stations.
Thank you, I will check information about Wimax system methodology V2.1 and compatibility with different systems.
Bear in mind, when discussing MPLS and connection admission control, MPLS has no built-in traffic policing mechanisms - only a range of rather complex priority-based bandwidth allocation methods. Once your LSP is admitted, it can exceed the requested bandwidth with no problem at all unless QoS mechansisms are also deployed.
The logical approach where bandwidth is unknown is traffic prioritisation rather than trying to enforce bandwidth limitations. You need to apply some sort of traffic classification rule at the point of ingress.
Yes, Daniel, MPLS has 8 levels of priority, but WiMAx has 5 classes. If I use all 8 priorities, I must create rules "to convert" priorities to classes of traffic. Because if in the network failure exists, it is obligatory to send traffic on different links, where in this moment traffic proceed and about additional traffic bandwith will be not enough, I will lose traffic with low priority. With high granularity (8 levels) I will send more traffic with medium to low priority, but with less granularity (5 levels) I guess, that it will lose more traffic. How overcome this problem?
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